"Yesterday I was diagnosed with breast cancer," she wrote in a Facebook post on July 25. "It came as a total shock as this dimpling (in the pic) is the only symptom I had."

While lumps are still the main indicator of breast cancer, many more subtle changes could also be crucial early-warning signs, such as redness or skin irritation, discharge or pain around the nipples, or, as Sherrie found, a few dents, or "dimpling.